BIG UPDATE: It's Adobe....well I'm 99% convinced Adobe CC Client is the culprit!
As per my previous posts I have been running stock Sierra installation for 3 days now without a single glitch, I installed Adobe CC client, Lightroom CC and Photoshop CC half an hour ago and the glitches are instantly back. I'm just waiting for another video to upload to YouTube so I can share it with you all but I had the screen glitch all over the screen for at least 4 minutes, changing resolution, wallpaper, GPU from discrete to intel made no difference it was persistent. Eventually switching the resolution multiple times caused something to clear and refresh the screen. This time I tried moving some windows through the glitch and it appears to move with it so perhaps some core graphics conflict with Adobe somewhere?
I think given my machine ran smoothly without any third party apps installed and then the instant I installed Adobe CC it started glitching is solid evidence that it's third party software to blame here and not hardware? Unless Adobe CC is "reaching" other parts of the hardware which a stock Sierra install simply doesn't reach?
Here's a 4 minute long video of the full screen glitch after installed Adobe CC Client, Lightroom CC and Photoshop CC. Note I wasn't even using the apps at the time, I had just logged back in. This wasn't the most colourful of glitches, I did have one that was a complete rainbow over the screen but unfortunately I didn't have my phone to hand so this one is less colourful but clearly glitching none-the-less.